What is a birthmark?

Birthmarks are flat, discolored marks on the skin with irregular borders. How they look varies depending on the type of birthmark and your child’s skin color. If your child has a mark on their skin, it is a good idea to see a healthcare provider who knows a lot about birthmarks.

Many birthmarks go away by themselves. Some types need to be watched carefully because they increase the risk of skin cancer. Others may need treatment because of bleeding or concerns about appearance. Rarely, a birthmark is a symptom of an underlying condition that needs treatment.

Other names for birthmarks are macular stains, stork bites, salmon patches and angel kisses.

  • What causes a birthmark?

    The exact causes are not known.

    Most birthmarks are not passed down from parent to child (not inherited). They are not caused by anything that happens to the mother during pregnancy.

  • Types of birthmarks

    There are 2 main types of birthmarks:

    • Vascular birthmarks are caused by problems with the tubes (vessels) that carry blood. Examples include infantile hemangiomas, capillary malformations and pyogenic granulomas (PDF).
    • Pigmented birthmarks happen because the substance that gives skin color (melanin) clusters in one part of the skin. These include café au lait spots, slate gray nevus and congenital moles.

Birthmarks at Seattle Children's

Our Vascular Anomalies Program is nationally known for treating children with birthmarks and other vascular disorders. We are 1 of the largest and most experienced programs in the United States.

We see nearly 2,000 children with vascular anomalies each year, more than any other hospital in the region.

For more information, contact the Vascular Anomalies Program by email or by calling 206-987-4606. If you would like an appointment, ask your child’s primary care provider to refer you.

Providers, see how to refer a patient

  • The experts you need for accurate diagnosis and care
    • We have the skill and experience to correctly diagnose your child’s birthmark. If tests are needed to confirm it, we have a broad range of imaging studies. Doctors with less experience might confuse a birthmark with another type of vascular anomaly, leading to the wrong treatment.
    • Our Vascular Anomalies team brings together experts with many different skills and experiences. These include otolaryngologists, dermatologists, plastic surgeons, general surgeons, ophthalmologists, geneticists and interventional radiologists.
    • Our team helps set national standards for care of young people with vascular anomalies. We provide the most advanced treatments in our region.
  • Team approach for complete care
    • We schedule visits so your child sees all the specialists they need in as few days as possible. In some cases, we can consult via video phone calls with doctors or patients.
    • Your child’s team will work together — and with you — to make a treatment plan that fits your child’s unique needs. Combining our skills helps make sure your child gets the very best care.
    • As long as needed, our team keeps a watch on your child’s condition. We are always here to answer your questions and connect you to community resources.
  • We treat your whole child
    • Children do not react to illness, injury, pain and medicine in the same way as adults. They need – and deserve – care designed just for them. Our experts focus on how treatments today affect growing bodies in the future. We provide the best and safest treatment for your child, based on our years of experience and the newest research.
    • At Seattle Children's, we work with many children and families from around the Northwest and beyond. Whether you live nearby or far away, we can help with financial counseling, schooling, housing, transportation, interpreter services and spiritual care. Read about our services for patients and families.

Symptoms of Birthmarks

Most often, birthmarks are flat, discolored marks with irregular borders. How they look depends on the type of mark and your child’s skin color. They may become darker with crying or room temperature changes. They fade with pressure, but when the pressure is removed, the discoloring returns.

  • Infantile hemangioma (hee-man-gee-OH-ma) is a cluster of extra blood vessels in or under the skin. It appears within 2 months of birth. It keeps growing for the first few months and then slowly fades.
  • Capillary malformation is a flat, discolored patch on your child's skin. It is often called a port wine stain because on some skin colors it looks like a splash of dark red (port) wine.
  • Pyogenic granuloma (PDF) looks like a single, raised bump. It can be any size and often grows fast. It bleeds easily, so it may look crusted and can turn into a sore.
  • Café-au-lait spot is darker than your child’s normal skin color.
  • Slate gray nevus is a large, blue-gray birthmark that looks like a bruise. Most appear on the lower back or buttocks. An old term for this birthmark is “Mongolian spot.”
  • Congenital mole is a raised spot on the skin, brown or black in color. The size varies.

Diagnosing Birthmarks

Most often, an experienced provider can diagnose your child’s birthmark by checking their skin carefully. It is important to make certain the mark is not a condition that needs treatment or careful watching. Some children have imaging studies to confirm the diagnosis or give us more information about the birthmark.

Treating Birthmarks

Most birthmarks do not need treatment. Many fade over time. Some need to be checked regularly because of a risk of skin cancer. Doctors may suggest removing a birthmark if it bleeds easily. If a birthmark affects your child’s appearance, they may want to have treatment to remove it or make it less noticeable.

  • Some infantile hemangiomas (IH) do not need treatment. Others can cause problems with vision, breathing or feeding. We treat IH with medicines such as propranolol, laser treatment and surgery, if needed.
  • Capillary malformations (port wine stains) may not need treatment. We watch for changes and, if needed, recommend laser treatment.
  • Pyogenic granulomas (PDF) are often removed because they may bleed easily. Surgery can take place in the clinic or operating room, depending on your child’s case. Sometimes we treat them with a skin cream called topical timolol.
  • Café-au-lait spots do not need treatment. But if your child has more than 5, it could be a symptom of neurofibromatosis.
  • Congenital moles (PDF) need to be watched for changes because there is a risk of a skin cancer called melanoma. At home, check each month for changes in the mole. Each year, visit the doctor to have your child’s mole checked. Sometimes we suggest removing a mole, but not all moles can be removed.
  • Slate gray nevus often fades without treatment.

Learn more about newborn rashes and birthmarks.

Contact Us 

If you have questions about a consultation or second opinion, email us or call 206-987-4606. If you would like an appointment, ask your child’s primary care provider to refer you.

Providers, see how to refer a patient

Paying for Care

Learn about paying for care at Seattle Children’s, including insurance coverage, billing and financial assistance.

For Healthcare Professionals